Ski slope or the like with layer of tree bark



Feb. 18, 1969 1. ZAMES 3,427,934

SKI SLOPE OR THE LIKE WITH LAYER OF TREE BARK Filed Aug. 51, 1966 INVENTOR, [RA ZAMZIS ygwwwa United States Patent 3,427,934 SKI SLOPE OR THE LIKE WITH LAYER 0F TREE BARK Ira Zames, NewYork, N.Y., assignor to American Can Company, New York, N.Y., a corporation of New Jersey Filed Aug. 31, 1966, Ser. No. 576,382 US. Cl. 94-3 Int. Cl. E01c 13/00; A63c 19/10 2 Claims ABSTRACT OF THE DISCLOSURE This invention relates to improvements of snowcovered recreational areas and the like and more particularly, to the use of an undercovering for snow which enhances and increases the utilization of recreational areas such as ski slopes, toboggan runs and the like.

Winter sports, particularly skiing, have become increasingly popular and many ski areas or resorts have been built at considerable cost to accommodate the large number of winter sportsmen. However, in many areas, the ski or winter sport season is relatively short because of the natural paucity of snow in that area. Further when, even in normal high snowfall areas, there is insufficient snow, utilization is reduced and the ski areas or resorts which expend substantial sums of money on maintenance of facilities and personnel, which are necessary to attract sportsmen, are faced with reduced income and serious financial losses. It would be desirable, therefore, to provide ways to facilitate utilization of such recreational areas to the fullest extent possible.

Heretofore attempts have been made to use synthetic or artificial snow for summer and winter skiing. It is known, for example, to use various materials such as pine needles, straw, sawdust, freely disbursed fibers and other similar materials which in some cases may be impregnated or coated with soap, wax, or the like. It is also known to make artificial snow from a mixture of thermoplastic resin with powdered wax sprayed on to a special covering provided on the ground. Further known substitutes for snow include synthetic resin particles bonded together with a synthetic resin latex, fused borax glass granules coated with acetic acid, and mineral gravel covered with a thin coating of lubricating oil.

None of these aforementioned or any other substitutes are known to have found practical acceptance to any large degree because these materials were either too expensive to manufacture, to apply and to maintain, they wore out too fast under the action of the weather and during actual use, or they gave poor skiing results.

Accordingly, objects of this invention include increasing the utilization of winter recreational areas such as ski slopes and the like by extending the season over which such areas may be enjoyed; reducing the amount of snow required, and thus the over-all operating costs, of winter recreational areas using man-made snow; preventing the growth of vegetation during the warm weather months and the necessity of having to cut it down prior to the skiing season each year; reducing the likelihood of damage to ski equipment and of injury to skiers;

3,427,934 Patented Feb. 18, 1969 in preparing new slopes, eliminating the requirement of having to remove rocks by explosives and thereby reducing the hazards attendant thereto; and beneficially utilizing a plentiful and relatively inexpensive by-product of a major industry.

These and other objects, advantages, and features of the invention which will appear as the description of the invention progresses are achieved by employing an undercovering for snow, whether the snow be natural, manmade or artificial. The undercovering forms a base for the snow and, as will be described in detail, provides increased utilization and other benefits for winter sports enthusiasts and operators of winter-sports resorts and ski slopes. The undercovering is formed with the material which is a by-product of industry and readily available at costs which make it economically feasible in the manner set forth. The material referred to is tree bark which is available in large quantities as a by-product of paper manufacturing, lumbering, and the like.

For a better understanding of the present invention reference should be had to the accompanying drawings wherein like numerals of reference indicate similar parts throughout the several views and wherein:

FIG. 1 is a schematic representation of a snow-covered ski slope having an undercovering of tree bark according to one embodiment of the invention.

FIG. 2 is a schematic representation of an enlarged section of the ski slope shown in FIG. 1.

Referring to the drawings, a layer of tree bark 10 of suitable height is distributed over a natural terrain 12 in a desired area, usually over bare ground although it can be applied over snow, but in any case preferably in the spring so as to maximize vegetation-growth inhibition. The bark thus forms a base for the snow 14, resulting in certain benefits among which is the tendency to prolong the length of the skiing season as compared to similar adjacent areas not having a bark undercovering.

At the beginning and end of the skiing season, when minimal snow is available, rocks and other objects tend to become a problem in that they protrude from the snow and reduce the usability of ski areas. These rocks frequently are the cause of damage to skis and skiing equipment and are sometimes the cause of injury to skiers. Even though there may be some snow on the ground, there may not be enough to cover the rocks sufiiciently. A layer of bark laid down before the first snow to a depth extending above the protruding rocks provides a suitable base for the snow whereby it will not be necessary to have as great a depth of snow as formerly required, the result being an extension of the skiing season.

Another reason that the skiing season is extended is that vegetation, for example, stems of grass, tend to protrude from the snow at the beginning and end of the skiing season when minimum quantities of snow are on the ground. These protruding stems adversely affect skiing and cause more rapid melting of'the snow. The use of an undercovering layer of bark precludes extensive growth of vegetation because, among other things, sunlight is excluded from the underlying terrain. Also the tannins in the bark are fairly toxic to plants thereby tending to prevent growth of any seeds or the like which are contacted by the tannins of the bark whether the seeds be in or on the ground or the bark.

In locations where man-made snow is supplied by snowmaking machines, it is often necessary to lay down a base layer of this snow to cover the rocks and fill in holes and the like, and thereafter to provide a covering layer over the base. The base layer is necessary to neutralize the adverse effects of the irregularities in the terrain and may vary in depth depending on the particular terrain. It is not uncommon, however, to require base layer depths in the order of one foot or so. According to this invention, a layer of bark may be laid on the natural terrain as a substitute for all or a portion of this layer of man-made snow. Since substantial expenses are involved in producing large quantities of man-made snow, and large quantities are generally required when the relatively large surface areas of ski slopes are considered, savings can be effected by the use of a bark base which only has to be laid down once and can be used season after season with very little maintenance requirements.

The discussion prior hereto pertains to the use of an undercovering of tree bark only. However, as may be found desirable, other materials may be mixed with the bark. For example, the bark may be used with such materials as straw, sawdust, wood shavings, pine needles, fibrous materials such as sisal and the like, plastic shavings, and various other materials, natural or man-made, as may be determined by the economics in the local area.

Bark emanating from debarking apparatus (e.g., debarking drums) of most paper-making plants ranges in size from small dust-like particles up to pieces which, in most cases, are not much larger than approximately 1 inch by 12 inches. However, at certain times of the year, some bark is easier to remove and may come out of the debarker in pieces ranging up to approximately 6 inches by 8 feet. These large pieces may be reduced in size to 1 inch by 12 inches or less. The bark may be used as produced. However, it may be desirable in certain cases to use a covering layer on the bark made up of material having a more uniform size than that produced in the aforesaid debarking apparatus. This would provide a smoother upper surface and reduce the tendency of large pieces of bark to protrude therefrom. This covering layer may be obtained by running some bark through a machine capable of reducing the size of the larger pieces. This reduced bark may be used to cover the standard size bark normally produced by the aforementioned debarking apparatus. The covering layer of reduced size may vary as desired, for example, by screening out and/or washing out the fines and dirt and/or reducing in size or rejecting any pieces having a dimension greater than approximately 6 inches. Instead of reduced bark for the covering layer, wood shavings, sawdust and other materials, previously mentioned, may be used.

Since the layer of bark does not erode with the spring run-01f, and since the bark prevents growth of vegetation, very little maintenance is required. Thus, once the bark is in place, it can be used from year to year with little, if any, work and expense to get it ready for each new season. This is contrasted to a conventional ski slope, Where vegetation (e.g., briars, brush, small trees) have to be cut before the first snow.

It is conceivable that after a number of years, the upper surface of the layer of bark may develop irregularities or perhaps the tannins in the bark may be leached out in which case there may be a tendency for vegetation to spring out from the underlying soil (e.g., where the depth of the layer of bark is minimal) or from the bark itself, as thistles and seeds fall thereon during the summer months. As may be required, therefore, the original layer of bark may be resurfaced to smooth out the irregularities and/or to provide the tannins to preclude growth of vegetation. This resurfacing layer ordinarily need not be as deep as the initial layer.

The bark of various types of trees may be used. However, it is preferable to use the bark of coniferous trees as they tend to produce bark chips within the size ranges previously indicated rather than large sheets, for example, as in the case of birch bark. Certain species such as balsam and aspen have a greater tendency to produce larger pieces of bark and it is preferable to avoid these during the sap season. The depth of the layer of bark will depend on various factors including the extent of irregularities in the underlying terrain. However, in most cases it is preferable to have an average depth of five inches or more.

In one example where an undercovering of bark has been used successfully, approximately one-half of the natural, grass-bearing terrain of a ski slope was covered with bark prior to the first snow. Approximately 750 tons of bark were used, but since the moisture content was 71%, the dry Weight amounted to approximately 218 tons. Approximately 21,000 square feet were covered. The average depth of bark was approximately 12.7 inches, the maximum depth being 29 inches and the minimum 1 inch. The first snowfall was on November 13 and this amounted to approximately 4 of an inch. All snow disappeared from both areas, i.e., the area covered by bark and the uncovered grass area, by May 4.

At the beginning of the skiing season, the following skiing conditions were observed:

Date Bark-Covered Area Grass Area With No Bark Nov. 25 Fair to good Not possible, grass too high above snow. Nov. 27-28 Good Fair, where packed. Dec. 4-5 .do Fair to good, where packed. Dec. 11-12 Very goo Good.

Bark-Covered Area Grass Area With No Bark Trails With D ate No B ark March 12. Very good... Good, some grass begin- Fair.

ning to show.

March 19 Good/fair Fair-h more grass show- D0.

March26 Fair Poor Out.

March 30 Good. Very poor, towline poor..- Out.

Apri12. Fair- Very poor, towline out, Out.

ground showing.

April9 do. Out Out.

April 16 Out Out Out.

It can be seen from the above that the bark-covered area was available for good skiing approximately two weeks earlier than the grass area, and at the end of the season good conditions lasted approximately 2% weeks longer on the bark area as compared to the grass area. In this example, therefore, the skiing season was extended a total of approximately 4 /2 weeks longer on the bark area as compared to the grass area. Assuming a normal duration of the season of 3 /2 months (15 weeks), this resulted in an increase of approximately 30% Besides extending the skiing season, the use of bark as an undercovering produces other benefits. The bark may be distributed in a manner to fill in many of the holes, crevices, and ground depressions to neutralize natural humps and form a smooth slope. This is particularly desirable for a beginners slope since it tends to diminish possible danger points for the less experienced skier. On the other hand, the tree bark may also be distributed to form artificial humps (sometimes called moguls) shaped as may be desired to enhance the enjoyment of the more experienced skiers who may find the more smoother surfaces boring.

Also the use of a bark undercover tends to reduce the damage to skis, particularly when there is a minimal depth of snow on the slope or on a particular area (e.g., at ski turns or along tow ropes). A ski breaking through the snow and contacting the bark will not likely be dam aged whereas if it contacted a stone or gravel, there is a greater likelihood that the skis will be scratched or more severely damaged. Since the layer of bark presents a soft and somewhat spongy surface (the extent thereof depending, among other things, on its depth) there is less likelihood of injury to fallen skiers.

An undercovering of bark at locations of heavy usage, for example, along tow ropes, will serve to extend the period of time over which the tow rope is usable. Since the areas along tow ropes are subject to this heavy use, frequently the snow therealong becomes unusable before the main ski slope which the tow rope services, thereby precluding full utilization of an otherwise usable slope. Use of a layer of bark along such towing rope would tend to cover rocks and protrusions, to fill in holes, depressions, crevices and the like, thereby making a smoother base for the snow. With this smooth undercovering, there would tend to be more even wear of the snow as compared to the Wear encountered on a natural irregular terrain. The term wear as used herein is intended to include melting, shifting, and the like of the snow which have debilitating effects thereon as far as its usability and enjoyment by sportsmen are concerned. The problems resulting from uneven wear of the snow is reduced by providing a smooth bark undercover as aforesaid.

Other benefits resulting from use of a bark undercovering include dispensing with the requirement of having to cut down vegetation (e.g., brush) that grows up each year and which tends to impair the skiing slope when winter arrives. Also the use of a layer of bark eliminates the requirement, in preparing a new ski slope, for blasting out protruding rocks, and of course, the attendant danger and hazards.

It also has been found that the layer of bark provides an excellent surface on which to run a tractor thereby facilitating servicing of a tow line and ski area during the summer months. Also it has been found that the layer of bark does not erode with the spring run-oft.

In addition to its use on slopes and along tow lines, a bark undercover may be used on trails. Less snow tends to fall on trails because they are generally more sheltered, for example, by overhanging trees. Thus, a bark undercover tends to facilitate greater utilization of this snow for the reasons previously mentioned. Also the use of bark on trails negates the adverse effects of rocks and other irregularities which tend to be more prevalent and which are harder to clear because of the greater inaccessibility of trails.

In addition to the aforesaid, it is believed that the tree bark, being more porous than the underlying soil (i.e., considering, among other things, the voids between the various pieces of bark) has less heat-retaining ability than the underlying soil so that less heat would be transmitted from the bark to the snow than would be transferred from the soil to the snow, the heat transmitted being that absorbed from the sun. In other words, the bark would tend to insulate the snow from the heat absorbed by the soil.

In addition to serving as an undercovering for snow, it is also possible to ski directly on the bark. Thus the layer of bark may serve a dual function of acting as an undercovering for snow during the cold weather months and as a skiing surface during warmer months.

Large numbers of trees are used each year by the paper-making industry, lumbering, and the like. Prior to entering the paper-making process, the bark is removed from the trees, and since it is not used in paper making, is a by-product for which few real beneficial uses have been found. In some cases the bark is used as a fuel but it is not an efficient fuel, among other reasons because of its high moisture content, and it is frequently burned primarily as a means of disposing of it. Essentially, therefore, the bark is considered a waste byproduct. In some cases, disposing of large quantities of 'bark may be a problem depending on the conditions in the local area. Because of the large quantities made available each year by the paper-manufacturing industry, and because no widespread beneficial use has been found for it, substantial quantities of this bark are available at relatively low cost.

It will be apparent from the above that there has been described an improvement for winter recreational areas and the like which utilizes readily available and economical undercovering for the snow.

It is believed that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement mentioned herein and in the steps and their order of accomplishment of the method described herein Without departing from the spirit and scope of the invention or sacrificing all of its material .advantages, the improvement herein described being merely a preferred embodiment thereof.

I claim:

1. In combination, a topographical slope having a predetermined area over which skiers are adapted to ski, pieces of tree bark stripped from logs with the aid of a manmade device from its natural occurring state on said logs covering said predetermined area to form a continuous layer of bark to an average depth of at least five inches in order to cover any underlying grass and rocks located on said predetermined area and reduce the extent and degree of natural occurring holes, protrusions, and the like irregularities, said tree bark having natural occurring tannins which are toxic to and tend to retard the growth of vegetation in the underlying terrain, and a layer of snow over said layer of bark providing a suitable surface for skiing.

2. The combination set forth in claim 1 wherein said bark is obtained from coniferous trees.

References Cited UNITED STATES PATENTS 175,273 3/1876 Cross 947 294,126 2/1884 Grillin 947 2,117,280 5/1938 Alexander 94-7 2,161,799 6/1939 Castberg 272-565 XR 2,742,288 4/ 1956 Brunel. 3,334,556 8/1967 Owen 94--19 XR JACOB L. NACKENOFF, Primary Examiner.

US. Cl. X.R. 272-56.5 

